Powered lift toilet seats are well known in the art. For example, U.S. Pat. No. 4,587,678 to Love, et al. describes a stationary frame with fixed handrails. A seat assembly is pivotally coupled to the stationary frame and a ball screw motor and lift arm are provided for pivotally moving the seat frame assembly relative to the stationary frame. While most toilet lift seats incorporate some form of pivoting seat assembly, U.S. Pat. No. 3,925,833 to Hunter describes a vertically movable toilet seat. Hunter employs a hydraulic cylinder for raising and lowering the seat as opposed to the electric motor of Love, et al.
Another version of an electrically operated toilet seat is described in U.S. Pat. No. 5,155,873 to Bridges, which has armrests that may be swung out of the way to enable an attendant to assist a disabled person in using the device. Another form of a hydraulically powered lift seat is described in U.S. Pat. No. 4,993,085 to Gibbons, which includes a pair of hydraulically operated lift assemblies with associated armrests which are tilted so as to cause the armrests to move in an upward and forward position as the mechanism is operated. The seat is provided with a second pair of hydraulically operated lifts in order to tilt the seat up and forward as the lift assemblies are operated.
U.S. Pat. No. 5,309,583 to White, et al. describes a powered toilet seat that has separate sets of mechanical linkages for raising and lowering a seat and for raising and lowering an armrest. While the seat is constrained to both lift and move forward slightly while it is being rotated forwardly, the armrests follow a circular arc in which the armrests initially move predominately in the upward direction and complete the motion by moving predominately in a forward direction. In addition, the armrests are maintained in a horizontal orientation at all time.
U.S. Pat. No. 6,470,513 describes a lift for placement over a conventional toilet. The lift includes a raising and lower mechanism which assists users in sitting and standing, a washing mechanism which is used to wash the lower extremities after toilet use, and a drying mechanism which is used to dry the lower extremities after use of the washing mechanism.